Calhoun is batting .227 (5 for 22) with one RBI, four runs and six walks in eight spring games.
"It's not possible -- without him being healthy," Matheny said. "He needed for everything to go right for that to be a possibility. It's definitely something that's holding him up.
"We kept saying we need to see him healthy before we can make any determination, and we say the same thing right now. We just thought we had kind of crossed that hurdle where we could watch him play on a consistent basis. Now we're held up again. He just hit another roadblock."